A fine fowl perches on a fine tree, as the old Chinese saying goes, but in Nagqu prefecture in the northern part of the Tibet autonomous region, there are simply no trees, fine or otherwise.

Located about 4,500 meters above sea level, Nagqu has thin air, a dry climate and sandy soil, with no natural trees.

"Trees are a rarity here, so birds usually nest on the ground with the rats and rabbits," said Sumje Tashi, Party chief of Nagqu.